Add initial JSON events

PROTOCOL.md

@@ -10,12 +10,17 @@ Log in to bgammon. A random username is assigned when none is provided.
 
 This must be the first command sent when a client connects to bgammon.
 
-### `json [on/off]`
+### `loginjson [username] [password]`
+
+Log in to bgammon and enable JSON formatted responses.
+
+All client applications should use the `loginjson` command to log in, as JSON
+formatted responses are more easily parsed by computers.  
+
+### `json <on/off>`
 
 Turn JSON formatted messages on or off. JSON messages are not sent by default.
 
-Graphical clients should send the `json on` command immediately after sending `login`.
-
 ### `help [command]`
 
 Request help for all commands, or optionally a specific command.
@@ -24,11 +29,11 @@ Request help for all commands, or optionally a specific command.
 
 List all games.
 
-### `create [public/private] [password]`
+### `create <public/private> [password]`
 
 List all games.
 
-### `join [id] [password]`
+### `join <id> [password]`
 
 Join game.
 

cmd/bgammon-cli/main.go

@@ -1,5 +0,0 @@
-package main
-
-func main() {
-
-}

cmd/bgammon-server/game.go

@@ -94,6 +94,17 @@ func (g *serverGame) sendBoard(client *serverClient) {
 	}
 }
 
+func (g *serverGame) playerCount() int {
+	c := 0
+	if g.client1 != nil {
+		c++
+	}
+	if g.client2 != nil {
+		c++
+	}
+	return c
+}
+
 func (g *serverGame) eachClient(f func(client *serverClient)) {
 	if g.client1 != nil {
 		f(g.client1)

cmd/bgammon-server/server.go

@@ -3,6 +3,7 @@ package main
 import (
 	"bufio"
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"log"
 	"math/rand"
@@ -184,7 +185,7 @@ COMMANDS:
 
 		// Require users to send login command first.
 		if cmd.client.account == -1 {
-			if keyword == bgammon.CommandLogin || keyword == "l" {
+			if keyword == bgammon.CommandLogin || keyword == bgammon.CommandLoginJSON || keyword == "l" || keyword == "lj" {
 				var username []byte
 				var password []byte
 				switch len(params) {
@@ -204,6 +205,10 @@ COMMANDS:
 				}
 				cmd.client.name = username
 
+				if keyword == bgammon.CommandLoginJSON || keyword == "lj" {
+					cmd.client.json = true
+				}
+
 				s.sendWelcome(cmd.client)
 
 				log.Printf("login as %s - %s", username, password)
@@ -215,6 +220,13 @@ COMMANDS:
 		}
 
 		clientGame := s.gameByClient(cmd.client)
+		clientNumber := 0
+		if clientGame != nil {
+			clientNumber = 1
+			if clientGame.client2 == cmd.client {
+				clientNumber = 2
+			}
+		}
 
 		switch keyword {
 		case bgammon.CommandHelp, "h":
@@ -256,6 +268,23 @@ COMMANDS:
 			}
 			opponent.events <- []byte(fmt.Sprintf("say %s %s", cmd.client.name, bytes.Join(params, []byte(" "))))
 		case bgammon.CommandList, "ls":
+			if cmd.client.json {
+				ev := bgammon.EventList{}
+				for _, g := range s.games {
+					ev.Games = append(ev.Games, bgammon.GameListing{
+						ID:       g.id,
+						Password: len(g.password) != 0,
+						Players:  g.playerCount(),
+						Name:     string(g.name),
+					})
+				}
+				buf, err := json.Marshal(ev)
+				if err != nil {
+					panic(err)
+				}
+				cmd.client.events <- buf
+				continue
+			}
 			cmd.client.events <- []byte("liststart Games list:")
 			players := 0
 			password := 0
@@ -357,18 +386,14 @@ COMMANDS:
 				continue
 			}
 
-			playerNumber := 1
-			if clientGame.client2 == cmd.client {
-				playerNumber = 2
-			}
-			if !clientGame.roll(playerNumber) {
+			if !clientGame.roll(clientNumber) {
 				cmd.client.events <- []byte("notice It is not your turn to roll.")
 				continue
 			}
 			clientGame.eachClient(func(client *serverClient) {
 				roll1 := 0
 				roll2 := 0
-				if playerNumber == 1 {
+				if clientNumber == 1 {
 					roll1 = clientGame.Roll1
 				} else {
 					roll2 = clientGame.Roll2
@@ -391,11 +416,7 @@ COMMANDS:
 				continue
 			}
 
-			playerNumber := 1
-			if clientGame.client2 == cmd.client {
-				playerNumber = 2
-			}
-			if clientGame.Turn != playerNumber {
+			if clientGame.Turn != clientNumber {
 				cmd.client.events <- []byte("failedmove It is not your turn to move.")
 				continue
 			}
@@ -432,7 +453,7 @@ COMMANDS:
 				}
 
 				originalFrom, originalTo := from, to
-				from, to = bgammon.FlipSpace(from, playerNumber), bgammon.FlipSpace(to, playerNumber)
+				from, to = bgammon.FlipSpace(from, clientNumber), bgammon.FlipSpace(to, clientNumber)
 
 				legalMoves := gameCopy.LegalMoves()
 				var found bool
@@ -443,7 +464,7 @@ COMMANDS:
 					}
 				}
 				if !found {
-					log.Printf("available legal moves: %s", bgammon.FormatMoves(legalMoves, playerNumber))
+					log.Printf("available legal moves: %s", bgammon.FormatMoves(legalMoves, clientNumber))
 					cmd.client.events <- []byte(fmt.Sprintf("failedmove %d/%d Illegal move.", originalFrom, originalTo))
 					continue COMMANDS
 				}
@@ -487,12 +508,7 @@ COMMANDS:
 				continue
 			}
 
-			playerNumber := 1
-			if clientGame.client2 == cmd.client {
-				playerNumber = 2
-			}
-
-			scanner := bufio.NewScanner(bytes.NewReader(clientGame.BoardState(playerNumber)))
+			scanner := bufio.NewScanner(bytes.NewReader(clientGame.BoardState(clientNumber)))
 			for scanner.Scan() {
 				cmd.client.events <- append([]byte("notice "), scanner.Bytes()...)
 			}

command.go

@@ -6,6 +6,7 @@ type Command string
 
 const (
 	CommandLogin      = "login"      // Log in with username and password, or as a guest.
+	CommandLoginJSON  = "loginjson"  // Log in with username and password, or as a guest, and enable JSON messages.
 	CommandHelp       = "help"       // Print help information.
 	CommandJSON       = "json"       // Enable or disable JSON formatted messages.
 	CommandSay        = "say"        // Send chat message.
@@ -20,3 +21,10 @@ const (
 	CommandBoard      = "board"      // Print current board state in human-readable form.
 	CommandDisconnect = "disconnect" // Disconnect from server.
 )
+
+type EventType string
+
+const (
+	EventTypeWelcome = "welcome"
+	EventTypeJoined  = "joined"
+)

event.go

@@ -1,8 +1,78 @@
 package bgammon
 
+import (
+	"encoding/json"
+	"fmt"
+)
+
 // events are always received FROM the server
 
 type Event struct {
-	Player int
-	Command
+	Type   string
+	Player string
+}
+
+type EventWelcome struct {
+	PlayerName string
+	Clients    int
+	Games      int
+}
+
+type EventJoined struct {
+	GameID     int
+	PlayerName string
+}
+
+type GameListing struct {
+	ID       int
+	Password bool
+	Players  int
+	Name     string
+}
+
+type EventList struct {
+	Games []GameListing
+}
+
+type EventSay struct {
+	Message string
+}
+
+type EventBoard struct {
+	GameState
+}
+
+type EventRoll struct {
+	Roll1 int
+	Roll2 int
+}
+
+type EventMove struct {
+	Moves [][]int
+}
+
+func DecodeEvent(message []byte) (interface{}, error) {
+	e := &Event{}
+	err := json.Unmarshal(message, e)
+	if err != nil {
+		return nil, err
+	}
+	switch e.Type {
+	case EventTypeWelcome:
+		ev := &EventWelcome{}
+		err = json.Unmarshal(message, ev)
+		if err != nil {
+			return nil, err
+		}
+		return ev, nil
+	case EventTypeJoined:
+		ev := &EventJoined{}
+		err = json.Unmarshal(message, ev)
+		if err != nil {
+			return nil, err
+		}
+		return ev, nil
+	default:
+		return nil, fmt.Errorf("failed to decode event: unknown event type: %s", e.Type)
+	}
 }